Combination toggle and pressure switch



P 7, 1968 J. E. MAAS 3,402,271

COMBINATION TOGGLE AND PRESSURE SWITCH Filed Sept. 28, 1966 FIGI l4 :20

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' \2 ,z 34 3s Q SHUT DOWN T SWITCH q MAGNETO L STARTING SWITCH 66 PRESSURE ENGINE O\\\SWITCH OILER CHAIN SAW INVENTOR JOHN E.. MAAS ATTORNEYS United States Patent 3,402,271 COMBINATION TOGGLE AND PRESSURE SWITCH John E. Maas, Valparaiso, Ind., assignor to McGill Manufactoring Company, Inc., Valparaiso, Ind., a corporation of Indiana Filed Sept. 28, 1966, Ser. No. 582,576 Claims. (Cl. 200-83) This application pertains generally to electric switches and more particularly to a combined toggle and pressure switch.

In many engine installations it is desirable to have a low pressure cutoff switch for shutting down the installation if a fluid used in the system drops below a predetermined pressure. For instance, if the installation were not shut down upon loss of lubrication oil pressure serious damage would be sustained by it. Most of the installations also provide a manual cutoff switch for stopping the operation when the operator so desires. It has been common in the past to have two separate switches to provide these different shut down operations. This leads to increased costs both for the switch manufacturer who must use a greater number of parts and to the installation manufacturer who must install two separate switches. In addition, the use of the two separate switches requires relatively more space in the installation.

It is an object of this invention to provide a combined toggle shut down and low pressure cutoff switch.

It is another object of this invention to provide a combined toggle shut down and low pressure cutoff switch that reduces the space requirement for the switches in an operating installation.

It is a further object of this invention to provide a combined toggle shut down and low pressure cutoff switch that is relatively inexpensive to manufacture and install in an operating installation.

In the drawings:

FIG. 1 is a front elevation view in cross-section of the switch device in accordance with this invention;

FIG. 2 is a side elevation view in cross-section of the device of FIG. 1; and

FIG. 3 is a schematic wiring and block diagram showing a typical system utilizing the device of this invention.

In one embodiment of this invention a combination tog gle and pressure switch is mounted in a common switch casing. A common terminal for the switch extends into the switch casing and is supported therewithin. A conducting pin is spring mounted within a cavity in the bottom of the toggle actuating bat so that the spring biases the pin into contact with the common terminal and also acts to capture the bat in the casing. In the first or closed position for the toggle switch, the bat is positioned so that the common terminal is grounded through the conducting pin and bat to the switch casing. In the second or open position for the switch, the bat is moved so that contact between the conducting pin and the common terminal is broken.

The pressure switch has a housing that is supported within the switch casing and includes a chamber which is open at one end of the housing, A diaphragm is secured across the open end of the chamber and fluid under pressure is applied to the bottom of the diaphragm. A contact is supported by the diaphragm and moves with it between first and second positions. A spring is mounted within the chamber of the pressure switch housing and serves to couple the contact to the common terminal and also biases the diaphragm and contact to a first position when the pressure on the diaphragm is less than the spring pressure, to couple the contact through the switch casing to a reference potential. When the pressure on the diaphragm is greater than the spring pressure, the diaphragm and contact are biased to a second position to break the coupling between the contact and casing to open the switch.

Referring to the figures of the drawings, FIGS. 1 and 2 show the combination toggle and pressure switch of this invention. The combined switches have a common switch housing which is a good electrical conductor. The toggle switch includes a bat 12 having a ball portion 14 and a cavity 15 therein opening at the bottom of the bat 12. A metallic bushing 17 is integral with the switch casing 10 and provides a seat for the ball portion 14 when mounting the bat 12 within the switch casing 10. A spring 20 is inserted in the cavity 15 between the end of the cavity and the base of an electrical conductor, pin 22, which is inserted into the mouth of the aperture. A terminal or pole 24 common to both the toggle and pressure switch extends through the casing 10 and is mounted therewithin to the top of insulated housing 26 of the pressure switch by conducting rivet 28. The spring 20 biases the pin 22 against the head 27 of rivet 28 in the first position of the bat 12 and also biases the ball portion 14 in the bushing 17 to capture the bat in position within the bushing. In the second position of the bat 12, the pin 22 is biased by the spring 20 in the pocket 29 (FIG. 2) of the insulated housing 26 so that the pin is not electrically coupled to the terminal 24 through the rivet 28.

Housing 26 has a chamber 30 therewithin which is opened at the bottom. A conductive plate or annular washer 32 is located in the top of the chamber 30 and is also secured thereto by the conducting rivet 28. A cap 34 which is a good conductor fits about a flange portion 36 of the housing 26 and contacts the switch casing 10. A diaphragm 38 of rubber, for instance, is then mounted on a shoulder portion 40 of the cap 34 across the opening in the bottom of the housing 26. A second conducting rivet 42 extends through the diaphragm 38 and fixes conductive stop plate 44 to the top side of the diaphragm 38 and secures an electrical contact 46 to the bottom side of the diaphragm. In the top 48 of the cap 34 is an eyelet 50 that has a conductive base 52 in contact with the cap 34. The eyelet 50 provides an opening for fluid under pressure to enter the space within the cap and to press against the bottom of the diaphragm 38.

A spring 54 is set within the chamber 30 of the housing 26 and is compressed between the conductive plate 32 and the stop plate 44. When the pressure on the bottom of the diaphragm 38 is less than the spring pressure, the spring biases the contact 46 into engagement with the base 52 of the eyelet 50 and electrically couples the contact 46 to the cap 34 and casing 10. When the pressure on the bottom of diaphragm 38 is greater than the spring pressure, however, the diaphragm will move against spring pressure cam pressing the spring in the chamber 30 and breaking the coupling between the contact 46 and the cap portion 34.

An installation using this combined toggle and pressure switch is shown in the combination block and circuit diagram of FIG. 3. An internal combustion engine has a magneto 63 supplying a potential for the engine ignition system. The toggle shutdown switch 62 and the pressure cutolf switch 64 are connected in parallel and coupled through a starting switch 66 to the magneto circuit. The fluid input to the pressure switch 64 in this example is from an automatic oiler 68 which oils, for instance, a chain saw 70 driven by the engine 60.

Upon starting the engine, because there is no oil pres sure from the oiler 68, the spring 54 biases the contact 48 into contact with the eyelet 50 to couple the contact to a reference potential through the conducting rivet 28, conductive plate 32, spring 54, conducting rivet 42, stop plate 4-4, contact 46, eyelet 50 and through cap 34 to the casing to close the switch. With the switch 64 closed, the magneto 63 is short circuited so that it is not possible to start the engine 60. Therefore, the normally closed starting switch 66 is provided in the circuit between the magneto 63 and the combined toggle and pressure cutofi switch. When starting the engine, this switch is opened thereby effectively removing the toggle switch 62 and the pressure switch 64 from the circuit. After the engine is running the oil pressure from the oiler 68 is built up to an amount that will open the normally closed pressure switch 64, and the starting switch 66 is closed. The shutdown switch 62 is opened upon starting the engine by moving the pin 22 into pocket 29 of the housing 26. Therefore, with both the shutdown and cutofi? switches open, the magneto circuit is open and supplying a potential for engine ignition.

If the operator desires to shut down the engine he switches the toggle switch 62 to the closed position to ground the terminal 24 and hence the magneto 63 through the conducting rivet 28, conducting pin 22, the bat 12, and bushing 17 to the casing 10 of the switch. If during normal operation, the oil pressure from the oiler drops below a predetermined amount, the spring pressure will be greater than the oil pressure and will bias the contact 46 into contact with the bottom plate 52 of the eyelet 50 to electrically couple the contact 46 to the casing 10 thereby closing the switch and short circuiting the magneto circuit 63 to shut the engine down.

What has been described, therefore, is a combined toggle shutdown switch and low pressure cutofi switch that reduces space requirements for the switches in an operating installation and which is relatively inexpensive to manufacture and install.

I claim:

1. A combination toggle and pressure switch including in combination, a switch casing, a first conducting member supported by said casing, actuating means for the toggle switch mounted within said casing and being movable to first and second positions, said actuating means being electrically coupled to said first conducting member in said first position, a common terminal extending into and being supported within said casing, means for electrically coupling said common terminal to said actuating means with said actuating means in said first position to complete the connection between said terminal and said first conducting member, a housing for the pressure switch being supported within said switch casing and having a chamber therein open at one end, a diaphragm, means for securing said diaphragm across the open end of said chamber, means for applying a pressure to said diaphragm, contact means supported by and movable with said diaphragm, a second conducting member supported by said switch casing, means for electrically coupling said terminal to said contact means, spring means within said housing chamber, said spring means acting to bias said diaphragm and contact means to a first position with the pressure on said diaphragm being less than said spring pressure, said contact means being moved to a second position with the pressure being greater than said spring pressure, said contact means being coupled to said second conducting member in one of said first and second positions of said contact means.

2. A combination toggle and pressure switch including in combination, a switch casing, actuating means for the toggle switch mounted within said casing and being movable to first and second positions for closing and opening the switch respectively, means electrically coupling said actuating means to a reference potential in said first position, a terminal extending into and being supported within said casing, means for electrically coupling said terminal to said actuating means with said actuating means in said first position, an insulated housing for the pressure switch having an opening therein, a diaphragm, cap means for securing said diaphragm across the opening in said housing, means for applying a pressure through.

said cap means to said diaphragm, said housing being supported within said switch casing with said cap means contacting said casing, contact means extending from said diaphragm into a space within said cap means, spring means within said housing biasing said diaphragm outwardly from said housing and said contact means moving therewith into electrical contact with said cap means, and means including said spring means for electrically coupling said terminal to said contact means so that said spring means acts to bias said contact means to electrically couple the same to a reference potential through said cap means to close the pressure switch with the pressure on the diaphragm being less than said spring pressure, and said diaphragm moving to break the coupling between said contact means and said casing with the pressure on the diaphragm being greater than the spring pressure, to open the pressure switch.

3. The combination toggle and pressure switch of claim 2 wherein said actuating means includes a bat having a ball-shaped portion and a cavity therein, said means for coupling said actuating means to a reference potential includes a bushing integral with said switch casing, said bat being movably mounted to said casing by positioning said ball-shaped portion in said bushing, and said means for electrically coupling said terminal to said actuating means includes a conducting rivet securing said terminal to said housing, a conducting pin and a spring, said spring and said pin being inserted in the cavity of said bat so that with said bat in the first position said spring biases said ball-shaped portion into said bushing and said conducting pin into contact with said rivet thereby electrically coupling said terminal to said switch casing through said bat and said bushing to close the toggle switch.

4. The combination toggle and pressure switch of claim 2 wherein said means for applying a pressure through said cap means to said diaphragm includes an eyelet extending through the top of said cap means, and said means for coupling said terminal to said contact means includes a conductive plate, a first conducting rivet securing said terminal and said conductive plate to opposite sides of the top of said housing, a second conducting rivet and a conductive stop plate, said second rivet fixing said stop plate and said contact means to the opposite sides of said diaphragm, and said spring means of a conductive material and being compressed between said conductive plate and said stop plate and biasing said contact means into connection with said eyelet to electrically couple said terminal to said switch casing through said cap means to close the pressure switch.

5. In a system including an internal combustion engine having a magneto and a starting switch for open circuiting the magneto upon starting the engine, and using a fluid at a predetermined pressure a combination shutdown toggle switch and low fluid pressure cutoff switch the improvement comprising, a switch casing, a terminal common to both switches having one end extending into and being supported within said casing, and the other end being adapted to be coupled to the magneto circuit, actuating means for the toggle switch movable between first and second positions for opening and closing the switch respectively, said actuating means coupling said common terminal to a reference potential in said second position thereby short circuiting the magneto circuit to shut the engine down, a housing for the pressure switch having an open chamber therein, a diaphragm covering the open end of said chamber, contact means coupled to said diaphragm and movable therewith, coupling means for electrically coupling said contact means to said switch casing, and spring means biasing said diaphragm and contact means coupled thereto into contact with said coupling means, with the fluid pressure being less than the predetermined pressure to close the pressure switch to short circuit the magneto thereby shutting the engine down.

References Cited UNITED STATES PATENTS Hufford 20083.4 XR Morrison 20083.4 Janos 200-83 XR Cromwell 20083.4 Scholz 20083.4 Packer et al 20083 10 ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner. 

1. A COMBINATION TOGGLE AND PRESSURE SWITCH INCLUDING IN COMBINATION, A SWITCH CASING, A FIRST CONDUCTING MEMBER SUPPORTED BY SAID CASING, ACTUATING MEANS FOR THE TOGGLE SWITCH MOUNTED WITHIN SAID CASING AND BEING MOVABLE TO FIRST AND SECOND POSITIONS, SAID ACTUATING MEANS BEING ELECTRICALLY COUPLED TO SAID FIRST CONDUCTING MEMBER IN SAID FIRST POSITION, A COMMON TERMINAL EXTENDING INTO AND BEING SUPPORTED WITHIN SAID CASING, MEANS OF ELECTRICALLY COUPLING SAID COMMON TERMINAL TO SAID ACTUATING MEANS WITH SAID ACTUATING MEANS IN SAID FIRST POSITION TO COMPLETE THE CONNECTION BETWEEN SAID TERMINAL AND SAID FIRST CONDUCTING MEMBER, A HOUSING FOR THE PRESSURE SWITCH BEING SUPPORTED WITHIN SAID SWITCH CASING AND HAVING A CHAMBER THEREIN OPEN AT ONE END, A DIAPHRAGM, MEANS FOR SECURING SAID DIAPHRAGM ACROSS THE OPEN END OF SAID CHAMBER, MEANS FOR APPLYING A PRESSURE TO SAID DIAPHRAGM, CONTACT MEANS SUPPORTED BY AND MOV- 